It makes good tea, I have saved quite a bit of used kava root in the freezer to, all at once, gather a large amount in my strainer and squeeze in a lot of hot water. This tea lasts me 2 or 3 days.
I sacrifice a little potency by heating the roots to 165 degrees then straining (no squeeze!) to make sure none of the roots were contaminated by my hands, freezing, or being left out. I'm really good at it, but that water I throw out is usually worth it. You can also brew green tea twice, yerba mate 3 times, and chaga 10 to 15 times. I have even brewed coffee twice in times of need. Do it! Enjoy your tea!